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Haptic soldiers guided by buzzing belt

By Duncan Graham-Rowe

THE US army is testing a navigation device that allows soldiers to feel their way, literally, through the fog of war. The device, a haptic belt, feeds information to the wearer through coded vibrations and can also relay orders given as hand signals via a glove that recognises gestures.

Navigation can be extremely difficult for soldiers, especially at night, says Elmar Schmeisser, who has been leading the work at the Army Research Office in North Carolina. GPS devices are not ideal as they require soldiers to take their eyes off their surroundings and their hand off their weapon. The illuminated displays can give away their position at night, too.

So Schmeisser has spent the last few years working with different companies and research groups to find an alternative. He and his colleagues have now developed a range of vibrating mini electric motors known as tactile actuators, or “tactors”, and tested them in various configurations. “What’s best is a belt around the torso with eight tactors signifying the eight cardinal directions,” says Linda Elliott, a psychologist who has been testing the systems on soldiers during training exercises at the Army Research Laboratory at Fort Benning in Georgia.

The tactors vibrate at 250 hertz, which is just enough to give a gentle but noticeable buzz around the torso at regular intervals indicating the direction in which the soldier needs to travel to reach the next waypoint.

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The belts are hooked up to a regular GPS device to access directional information, as well as an accelerometer and digital compass. These mean the device knows which way the soldier is facing, even if they are lying down. “As long as you are going in the right direction you will feel it on your front,” says Elliott, who will be presenting the technology at the Human-Computer Interaction conference in Orlando, Florida, in July. “As you get to within 50 metres of the waypoint all the tactors start to go off, and within 15 metres they will quicken.”

Besides directions, the tactors can communicate commands such as “halt”, signified by the front, back and side tactors pulsing simultaneously, or “move out”, when they pulse from back to front, almost as if they were pushing the soldier forward.

While commands could be sent from base, Schmeisser and Elliott are also working with a company called AnthroTronix, which has developed a glove that has integrated accelerometers to detect hand gestures. The hope is to allow a platoon leader to be able to communicate with their squad while out in the field through standard military hand gestures sent wirelessly to their belts, says Elliott.

It’s an interesting and useful development, says Katherine Kuchenbecker, director of the haptics group in the University of Pennsylvania’s GRASP lab, in Philadelphia. Her group has previously made a haptic vest for first-person shooter video games, where the tactors are activated to simulate a shot when the player is hit. “Conveying directional information through the skin is a nice complement to seeing and hearing one’s surroundings,” she says.

Elliott has tested the haptic belt on a number of different army personnel, from rangers to snipers, as they carried out six training exercises during the day and night. They were required to carry out various tasks, such as responding to requests for information and searching for targets, while navigating at the same time.

“We compared the performance with a handheld Garmin GPS and a traditional map and compass,” says Elliott. Based on navigation time, errors en route and targets detected, the belt not only performed as well but the consensus among soldiers was that they loved it, because they didn’t need to put down their weapon or take their eyes off their surroundings. As one soldier put it&colon; “It is hands and thought-free.”

Soldiers loved it, because they could navigate without taking their eyes off their surroundings